1. Field of the Invention
The present invention relates to a power estimator for microprocessors having a plurality types of memories such as a main memory, cache memories and the like in order to estimate a power consumption of instructions to be executed by a microcomputer or a microprocessor based on assembler descriptions in a program.
2. Description of the Related Art
Recently, there is a strong trend toward miniaturization, portabilization and mobilization of electronic devices, in particular, personal-computers, by the recently great progress of the computer technology field and of the semiconductor integrated circuit field. In this trend, the power consumption of a microprocessor and the increasing of the processing speed of the microprocessor become very important problems. In order to reduce the power consumption of the microprocessor, it must be required to measure the power consumption of the microprocessor accurately.
For example, the following literature describes the power consumption estimation method for microprocessors including software:
"Power Analysis of Embedded Software: A First Step towards Software Power Minimization", Vivek Tiwari, Sharad Malik, Andrew Wolfe, IEEE-94, PP.384-390, 1994.
The power consumption estimation method disclosed in the above literature is the method to estimate the power consumption based on the types of instructions to be executed actually by a microprocessor. That is, the power consumption of each of instructions to be executed by a microprocessor is measured and stored into a memory in advance. Then, the total power consumption of the microprocessor is measured by applying the power consumption value of each of the instructions, which have been stored in the memory in advance, to instructions to be actually executed in assembler instruction level.
As described above, there is the conventional power consumption estimation method used for microprocessors based on instructions in software programs. However, the conventional power consumption estimation method may estimate no power consumption of microprocessors in consideration for cache memories.
That is, in the conventional power consumption estimation method, it is difficult to estimate the power consumption of microprocessors having cache memories by distinguishing it from the power consumption of microprocessors having no cache memories.
In general, since the power consumptions of cache memories are changed based on their configurations such as the accessing speed and the memory sizes, the power consumption of the microprocessor is changed based on that the instructions are accessed from which type of the cache memory.
However, the conventional power consumption estimation method can not distinguish both the power consumption of a microprocessor including cache memories and the power consumption of a microprocessor including no cache memories. That is, the conventional power consumption estimation method estimates that the power consumption values of both the cases become the same value. Therefore there is the drawback in the conventional power consumption estimation method that it is difficult to estimate the power consumption of microprocessors in instruction level accuracy.